The invention concerns a filter element, in particular an interior air filter for filtering air for the interior (passenger compartment, cabin) of a motor vehicle. Moreover, the invention concerns a housing for such a filter element and a filter arrangement with such a filter element.
A filter element of this kind serves for filtering fluid streams or gaseous media, for example, for filtering an air stream that is supplied to the vehicle interior of a motor vehicle. Even though the present invention can be applied to any type of filter element and filter arrangement, the present invention as well as the problem to be solved will be explained in the following for a filter element for filtering air for the interior of a motor vehicle. In the following, such filters will be referred to for short as automotive interior air filter or simply interior air filter or cabin air filter.
With increasing air pollution, in particular in large cities, in combination with the use of modern air-conditioning devices, it is desirable and also necessary to purify by means of suitable filters the air that is supplied from the exterior into the interior of a motor vehicle and treated and air-conditioned. For this purpose, for example, particle filters, odor filters or their combination with each other are conceivable which remove or absorb airborne particulate material, particles and odors as much as possible from the ambient air. Such filters for filtering air for the interior of a motor vehicle are generally known in a plurality of embodiments and variants so that their configuration and function will be explained only briefly in the following.
Since the efficiency of filters depends in particular on the size of the surface area through which the air flows, in automotive interior air filters primarily zigzag-shaped folded filter media are used that are referred to also as pleated filter media. By folding the employed filter medium, depending on the height of the folds, the fold spacing, and the degree of compression of this accordion-like fold pack or the different fold sections of the filter medium, an enlargement of the filter surface area through which the air stream can flow is enabled. In order to be able to better handle and manipulate such filter elements with zigzag-shaped folded filter media, in particular with respect to assembly, reinforcement elements are often provided on the sides of the filter element across the filter pack of the folded medium. These reinforcement elements serve for lateral fixation and stabilization of the zigzag-shaped filter medium and are attached, for example, by means of a suitable adhesive, to the lateral edges of the fold pack. These reinforcement elements are referred to also as side bands. The filter element with the strip-shaped reinforcements and fortifications applied along folded longitudinal sides can therefore be handled and inserted in a simple way with regard to installation into a housing of a filter module or an appropriate filter receptacle, for example, into a filter housing or an air-conditioning device of motor vehicle, without causing damage to the filter element.
DE 10 135 691 discloses a filter insert for a filter housing that comprises a filter pack whose two exterior sides are each provided with a sealing strip. One of the sealing strips has a first leg and a second leg wherein the width of the first leg is matched to the height of the filter pack. The second leg has a reduced width in comparison to the first leg or the filter pack. In the inserted state in the filter housing, the second leg is contacting the first leg at an acute angle. When not installed, the first leg and the second leg are positioned relative to each other at an obtuse angle.
DE 195 32 436 C1 discloses a further filter insert with a fold pack that is provided along its two exterior sides with a seal, respectively. The width of the seal is greater than and at most twice the height of the exterior side of the fold pack. The seal has a fold.
With the afore described solutions, the filter pack can be reliable sealed in case of a correct installation in a filter housing. However, this sealing action in the described solutions is ensured only for the prescribed installation direction; for example, in case of installation opposite to the predetermined flow direction the seals are not effective. Since the projecting legs of the described solutions during installation can be pressed simply against the exterior walls of the filter pack, a faulty or erroneous installation is possible anytime.
DE 10 2009 042 588 A1 discloses a filter element in which defined geometrically shaped edge elements are attached to the edge of the filter pack.